Relationship between Material Fracture Toughness using Fracture Mechanics and Transition Temperature Tests

Although the effect of flaws in stressed bodies can be quantitatively characterized by methods of linear elastic fracture mechanics (LEFM), it is sometimes necessary to assess the fracture susceptibility using only conventional transition temperature tests. In order to gain the advantages and best features of each approach, a correlation between the two methods of fracture assessment is needed. The existing correlation between LEFM results and transition temperature test results are reviewed in light of new data on A533B steel. A complete series of test results obtained by the HSST Program (ORNL) for both LEFM and transition temperature tests in both unirradiated and irradiated conditions permit fracture toughness to be correlated with charpy V-notch energy, nil-ductility transition temperature, DT transition temperature, and low temperature cleavage stress. By following fundamentals of LEFM, whenever possible, a consistent pattern of fracture behavior is demonstrated for a class of pressure vessel steels similar to A533B. /Author/